package com.xiaohong.gateway.filter;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.http.codec.support.DefaultServerCodecConfigurer;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.cors.reactive.CorsUtils;
import org.springframework.web.filter.reactive.HiddenHttpMethodFilter;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import reactor.core.publisher.Mono;

/**
 * @ClassName CorsConfig
 * @Description html gateway跨域配置
 * @Date 2019/9/5 14:00
 **/
//@Configuration
public class GlobalCorsConfig {
    private static final String MAX_AGE = "18000L";

//    @Bean
    public WebFilter corsFilter() {
        return (ServerWebExchange ctx, WebFilterChain chain) -> {
            ServerHttpRequest request = ctx.getRequest();
            if (CorsUtils.isCorsRequest(request)) {
                HttpHeaders requestHeaders = request.getHeaders();
                ServerHttpResponse response = ctx.getResponse();
                HttpMethod requestMethod = requestHeaders.getAccessControlRequestMethod();
                HttpHeaders headers = response.getHeaders();
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_ORIGIN, requestHeaders.getOrigin()); // #允许向该服务器提交请求的URI，*表示全部允许，在SpringMVC中，如果设成*，会自动转成当前请求头中的Origin 但当请求中要传给服务器cookie数据时能写*前台会报错
//                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_HEADERS, "Origin, No-Cache, X-Requested-With, If-Modified-Since, Pragma, Last-Modified, Cache-Control, Expires, Content-Type, X-E4M-With,userId,token");
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_HEADERS, "*"); // #允许访问的头信息,*表示全部
                headers.add(HttpHeaders.ACCESS_CONTROL_ALLOW_CREDENTIALS, "true"); // 允许cookies跨域
                headers.add(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS, "Authorization,Captcha-Token"); // 配置前端js允许访问的自定义响应头
                headers.add(HttpHeaders.ACCESS_CONTROL_MAX_AGE, MAX_AGE); // 预检请求的缓存时间（秒），即在这个时间段里，对于相同的跨域请求不会再预检了
                if (request.getMethod() == HttpMethod.OPTIONS) {
                    response.setStatusCode(HttpStatus.OK);
                    return Mono.empty();
                }
            }

            return chain.filter(ctx);
        };
    }

//    Gateway内部已经配好了
//    @Bean
//    public ServerCodecConfigurer serverCodecConfigurer() {
//        return new DefaultServerCodecConfigurer();
//    }

    @Bean
    public HiddenHttpMethodFilter hiddenHttpMethodFilter() {
        return new HiddenHttpMethodFilter() {
            @Override
            public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
                return chain.filter(exchange);
            }
        };
    }
}

